Wordy Wednesday #455: Cooking in the JPEG Kitchen

Today is National Sponge Cake Day—the quintessential classic of the cake world

Digital imaging is, in most ways, more convenient than film photography. The ability to choose a white balance, select an ISO speed and view images on the fly, to name just a few. But there’s the inevitable question: JPEG or RAW?

JPEG is an acronym for Joint Photographic Experts Group who, in 1986, created the standard for digital still images that defines how an image is compressed and decompressed. To save an image in JPEG format, your camera makes adjustments to eliminate colors the eye can’t see and then compress the image. JPEG is referred to as a lossy (not lousy) format because this process discards what it decides is redundant but when the file is opened  lost data is, for the most part, rebuilt.

Midnight in Old San Juan

Unlike JPEG, RAW requires little or no internal processing by the camera. These files contain more color information, more data but that all that data now requires external processing. Perhaps these food analogies will help explain the difference between a RAW and compressed (JPEG) capture:

  • Cakes. You can purchase a ready-to-eat cake in a bakery or make one at home from scratch. The store bought cake is like a JPEG, since most of the choices were made for you. To meet bakery standards, they decide what ingredients to add and in what quantity. JPEG photographs are processed and compressed in-camera and you take it “as is.” On the other hand a scratch-made cake allows you to choose the ingredients, altering them to suit your personal taste. The same thing goes for RAW images. You decide how to process them in post-production.
  • Chocolate chip cookies. Off-the-shelf brands have chips are already baked into each one, the softness of the cookie predetermined and all are uniform in size. This is clearly the JPEG version. Cookies baked at home offers more choices: milk, dark, or white chocolate chips, the number of chips to fold into the batter and the size of the cookies baked. It’s the RAW version.

When should you use RAW and when should you use JPEG? There are lots of discussions on this subject on this blog and my friend Mark Toal offers his opinion at our sister blog—Mirrorless Photo Tips. Read what we both have to say and then make up your own mind.

light.bookMany thanks to master photographer Barry Staver for the cooking analogies. Barry along with myself are co-authors of Better Available Light Digital Photography that’s out-of-print with new copies available from Amazon for $19.95 (non-Prime) or used copies for giveaway prices, only $7 as I write this.

Author: Joe Farace

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